1. Field of the Invention
The invention refers to a movable device for openpit mining serving the purpose of excavating ground and/or rock, in particular ores, comprising a swivellable cantilever arm on which is mounted a hulking hammer.
2. Description of the Prior Art
In openpit mining there are primarily used big broaching vehicles, such as bucketwheel excavators, for excavating material. Such known devices of the mentioned type can, however, only be used for excavating rock having a cubic strength of approximately 20 MPa and can not be used for excavating in openpit mining rock or ore of greater hardness without precautions. When excavating harder rock, excavation must, as a rule, be interrupted for making bore holes and/or applying explosive charges for being then in the position to obtain correspondingly crushed material.
It is already known to mount on a cantilever arm a fluid-operated hammer and to loosen and to take up with such devices the surface layer of roads when performing, for example, construction work and repairing work, whereupon the thus crushed material can be transported away in a usual manner.
From U.S. Pat. No. 3,999,805 there has become known a kinkable support for a loosening tool, for example an excavating hammer or a loading shovel. The U.S. Pat. No. 4,025,116 shows and describes an excavating device by means of which a carrier comprising excavating spikes is forced under hydraulic pressure into the rock to be excavated, whereupon the rock is crushed by hydraulically lowering or lifting, respectively, the carrier.